* rename the file from exc to exceptions
* move CommandException to exceptions and change it to CommandError
* use argparse required=True instead of checking in the code
Change-Id: I67450ff0acb317fa1ab3996a094e871023f5383f
* check that limit is a positive number in 'vitrage topology show'
* check that time is an iso8601 timestamp in 'vitrage event post'
* add tests to check this
Change-Id: If5c4b26578f865c68709027b6e815376e4ee9e1e
add default conversion for exceptions
move the default headers
change the VersionInfo name
Change-Id: Icd74efdc32cd90e89f2321b0ec8da29d3555629a
Implements: blueprint vitrage-cli
